INFO: task rcu_tasks_kthre:12 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:rcu_tasks_kthre state:D stack:26992 pid:12 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5257 [inline]
__schedule+0x1089/0x4140 kernel/sched/core.c:6584
schedule+0xb9/0x180 kernel/sched/core.c:6660
schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2144
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x2c2/0x590 kernel/sched/completion.c:138
__synchronize_srcu+0x2b3/0x350 kernel/rcu/srcutree.c:1243
rcu_tasks_wait_gp+0x49d/0xb00 kernel/rcu/tasks.h:719
rcu_tasks_one_gp+0xb1c/0xce0 kernel/rcu/tasks.h:560
rcu_tasks_kthread+0x6e/0x90 kernel/rcu/tasks.h:588
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8db2e3f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xce0 kernel/rcu/tasks.h:543
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8db2ec30 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xce0 kernel/rcu/tasks.h:543
1 lock held by khungtaskd/28:
#0: ffffffff8db2daa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8db2daa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8db2daa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6669
2 locks held by getty/4030:
#0: ffff88814cada098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x430/0x1400 drivers/tty/n_tty.c:2198
2 locks held by kworker/1:5/4360:
#0: ffff888018472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90004137d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
4 locks held by kworker/u4:32/7457:
1 lock held by syz.3.4468/22943:
#0: ffffffff8db337b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#0: ffffffff8db337b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026
Call Trace:
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xf0e/0xf50 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 22943 Comm: syz.3.4468 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026
RIP: 0010:asm_sysvec_apic_timer_interrupt+0x0/0x20 arch/x86/include/asm/idtentry.h:690
Code: e9 f5 04 00 00 90 90 90 90 90 0f 01 ca fc 6a ff e8 f5 03 00 00 48 89 c4 48 89 e7 e8 ba 45 d7 ff e9 d5 04 00 00 90 90 90 90 90 <0f> 01 ca fc 6a ff e8 d5 03 00 00 48 89 c4 48 89 e7 e8 0a 44 d7 ff
RSP: 0018:ffffc90005917528 EFLAGS: 00000087
RAX: 0000000000000000 RBX: ffffea00019cc640 RCX: 423065b85dbde900
RDX: 0000000000000000 RSI: ffffffff81da6d91 RDI: ffffffff8db2daa0
RBP: ffff888058531af8 R08: ffffea00019cc647 R09: 1ffffd40003398c8
R10: dffffc0000000000 R11: fffff940003398c9 R12: ffffea00019cc658
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffffd40003398c9
FS: 00007f9869f326c0(0000) GS:ffff8880b8d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1c54df72f8 CR3: 000000005791e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
RIP: 0010:lock_release+0x1/0x920 kernel/locking/lockdep.c:5798
Code: 80 e1 07 80 c1 03 38 c1 0f 8c 67 fa ff ff 4c 89 f7 e8 a3 30 6f 00 e9 5a fa ff ff 41 be 2f 00 00 00 e9 70 fa ff ff 0f 1f 00 55 <48> 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec e0 00 00
RSP: 0018:ffffc90005917550 EFLAGS: 00000287
page_remove_rmap+0x7f5/0xef0 mm/rmap.c:1466
zap_pte_range mm/memory.c:1451 [inline]
zap_pmd_range mm/memory.c:1572 [inline]
zap_pud_range mm/memory.c:1601 [inline]
zap_p4d_range mm/memory.c:1622 [inline]
unmap_page_range+0x10db/0x25b0 mm/memory.c:1643
unmap_vmas+0x260/0x390 mm/memory.c:1728
exit_mmap+0x20d/0x970 mm/mmap.c:3293
__mmput+0x118/0x3a0 kernel/fork.c:1214
copy_process+0x2c46/0x4070 kernel/fork.c:2621
kernel_clone+0x24b/0x900 kernel/fork.c:2769
__do_sys_clone kernel/fork.c:2910 [inline]
__se_sys_clone kernel/fork.c:2894 [inline]
__x64_sys_clone+0x1a7/0x220 kernel/fork.c:2894
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9868f9fb19
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9869f31fd8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f9869225fa0 RCX: 00007f9868f9fb19
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000002c9a4080
RBP: 00007f9869037b70 R08: ffffffffff600000 R09: ffffffffff600000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f9869226038 R14: 00007f9869225fa0 R15: 00007ffc36a2fe88